1. Field of the Invention
The invention relates to a method for separating letters in which irregularly spaced and disordered piles of letters that are being transported on a conveyor belt are rendered into a continuous stream of letters that are largely not lying on top of each other and that are distributed virtually homogeneously over the conveyor belt. Moreover, the invention relates to a device that is suitable for carrying out the method.
2. Related Technology
An automated separation and sorting line usually includes a conveyor belt onto which boxes or sacks that are delivered at irregular intervals are emptied, as a result of which irregularly spaced and disordered piles of letters are formed on the conveyor belt.
The letters arranged on the conveyor belt in such a way are then normally fed to one or more successive separators with the objective of rendering the above-mentioned arrangement of the letters made up of disordered piles into an arrangement that is made up of letters that are largely not lying on top of each other and that are situated virtually homogeneously on the conveyor belt, thus corresponding to a continuous stream of letters that are largely not lying on top of each other and that are distributed virtually homogeneously on the conveyor belt.
An arrangement of a separator for separating letters is described in U.S. Pat. No. 2,905,309, especially in FIG. 1 thereof. In the disclosed arrangement, the letters initially reach a first conveyor belt via an inclined plane, whereby the conveyor belt conveys the letters to a second conveyor belt via a swing tray that exerts an influence on the regulation of the conveyor belt. This second conveyor belt feeds the letters to another separator that includes a rotating drum with protruding thin strips or “fingers ” that pull or push the letters individually off the conveyor belt and into a shaft. The drum is installed above the conveyor belt crosswise to the conveying direction in such a way that the strips can touch the conveyor belt and the drum in the described device rotates in such a way that the strips move in the conveying direction whenever they are below the axis of rotation.
The described arrangement and especially the transport via the swing tray that influences the regulation of the conveyor belt is carried out with the same objective as that of the method according to the invention, but is very complex. Moreover, in case of a high mail volume, it can happen that letters lying on the tray are pushed off by the subsequent letters so that the conveyor belt can no longer be regulated so as to be adapted to the mail volume and an overload of the system can occur.
However, such a method is not suitable for use in bulk processing of mailpieces as is carried out, for example, in mail centers.